Services

app/services/
  brands/           # Brand lifecycle
  campaigns/        # Campaign operations
  creators/         # Creator management
  metrics/          # Data ingestion and sync
  chat/             # Chat system
  notifications/    # Multi-channel notifications
  integrations/     # External services
  ...

Brands::PipelineStatusChange.new(
  brand: brand,
  new_status: "active",
  actor: current_user
).perform!

Creators::Rejector.new(
  user: creator,
  reason: "performance",
  notes: "Consistently missed cadence"
).perform!

Metrics::Ingestor.new.ingest_for_social(social, posts)

Mc::NotificationDispatcher.notify!(
  recipient_user_id: user_id,
  kind: Notifications::Kinds::EARLY_VIRAL_ALERT,
  title: "Going viral!",
  body: "Your post hit 100K views",
  target_url: "/brands/123"
)

# Good - single purpose
class Creators::TierPromoter
  def initialize(user:)
    @user = user
  end

  def perform!
    return unless eligible?
    @user.update!(tier: next_tier)
  end
end

def perform!
  ActiveRecord::Base.transaction do
    create_records!
    send_notifications!
    update_status!
  end
end

def perform!
  # Returns the created record or result object
  submission = CampaignSubmission.create!(attributes)
  Result.success(submission)
rescue ActiveRecord::RecordInvalid => e
  Result.failure(e.message)
end

def create
  result = Campaigns::PlacementAllocator.new(
    social: @social,
    posts: post_params
  ).perform!

  if result.success?
    render json: result.data
  else
    render json: { error: result.error }, status: :unprocessable_entity
  end
end

class Metrics::SyncJob < ApplicationJob
  def perform(social_id:)
    social = CreatorSocial.find(social_id)
    posts = fetch_posts(social)
    Metrics::Ingestor.new.ingest_for_social(social, posts)
  end
end

class Creators::TierPromoterTest < ActiveSupport::TestCase
  test "promotes user to next tier when eligible" do
    user = create_user(tier: "rocket", total_views: 15_000_000)
    
    Creators::TierPromoter.new(user: user).perform!
    
    assert_equal "moonwalker", user.reload.tier
  end
end